*
    margin 0
    padding 0 
    box-sizing border-box

ul,li
    list-style none

.accordion
    display flex
    width 600px
    height 200px
    line-height 200px
    text-align center
    color white
    transition flex .5s
    li
        flex 1
        cursor pointer 
        &:nth-child(1)
            background-color #f66
        &:nth-child(2)
            background-color #66f
        &:nth-child(3)
            background-color #f90
        &:nth-child(4)
            background-color #09f
        &:nth-child(5)
            background-color #01f
        &:nth-child(6)
            background-color #3c9
        &:hover
            flex 2
            // flex 2  手风琴的关键